Service Guys Clueless on error P0128

[werther]

Hi guys!

My first post! came here looking for good advice. Wished my first post was motivated by better reasons... but here we go.

Yaris 2008, 30k miles. Awesome car. Never failed me. Never missed a service. Bought in Mass. now in Texas border town.

Engine light on, checked with the reader: P0128.

Took it to the local Toyota dealership I always go for service. They kept the car 48 hours, told me it was the thermostat and its gasket something. They replaced all that, 300 bucks and off I went. After 24 hours, the same issue again.

This time the had the car for the weekend, and "they found" it was the thermostat cord and it was replaced, they did not dare to charge me.

At this point I am thinking "So, are they just trying different things? taking a shot at fixing the issue? they changed a perfectly working thermostat?"

OK. I drive the car 2 days... and AGAIN!!!

I drop off the car... it has been 8 days... and now they are saying it is something about the cord "don't know what" but something related to the cord.

Total? $1200.

So, I really don't know what to think. Some of you guys drove your Yaris for over 200k km... I can't think of how changing something that sounds so simple like a cord, can be $1200 bucks.

I would appreciate your thoughts/advice on this one. For now, I am not planning on getting it fixed with this guys, they looked to me totally incompetent.

Thanks!